That's insane behavior, I don't owe your business or site anything, least of all my time. Those are the kindest words I can find for that behavior.
It’s annoying and tacky but it’s not analogous to being held hostage.
That'd depend on the implementation behavior. If it's using window.onbeforeunload, yeah I guess it's kind of like someone blocking you when you try to leave, although you can easily walk around them (on most browsers if you try to close the tab and the modal shows up, and you try to close the tab again it will override the modal). However, there's also another type where it tracks the location of your cursor, and shows a popup when it leaves the content area (indicating that your mouse is going to close the tab or go back). In that case it's not really blocking anything, and much more analogous to a salesperson saying "before you go" as you're walking out the door.
Which is a solid ‘no thanks, not coming here again’ from me.
I would try to avoid going back to that store.
Many stores do indeed make it hard to leave without buying, for example by having no direct route to the exit: you have to squeeze through the tills awkwardly. It's probably in the name of loss prevention, but it's also a disincentive to leave without a purchase.
Actually, nearly everything about a supermarket is carefully designed for extracting money from you, from product placement, to layout, need to have a loyalty card to access discounts, even perhaps having discounts in the first place (as opposed to selling at a lower regular price), multipacks driving food and packaging waste, etc etc etc.
well the difference is that you've used more fancy words in the second description. Reminds me of the joke
"It should be noted that no ethically-trained software engineer would ever consent to write a DestroyBaghdad procedure. Basic professional ethics would instead require him to write a DestroyCity procedure, to which Baghdad could be given as a parameter."
If a customer is attempting to leave and you bar their exit, you've demonstrated a willful contempt of their wishes. It causes the customer stress and serves no purpose other than to show them that you can make them do as you please. It's a micro aggression, a type of violence.
Imagine a woman trying to leave a man's apartment as he holds the door closed. He reminds her she was the one who came inside and asks again, is she sure there's nothing she wants from him? He keeps his hand there until she says she's sure so she understands, he [i]let[/i] her leave.
I'm against either scenario for effectively the same reasons.
You mean don't ultimately prevent you. But they absolutely do temporarily stop you.